Loopers and looper throw-outs for chain-stitch sewing machines



E. A. MUECKE Aug. 14, 1956 2,758,557 LOOPERS AND LOOPER THROW-OUTS FORCHAIN-STITCH SEWING MACHINES 3 Sheets-Sheet 1 Filed Dec. 8, 1954INVENTOR. Edward A. Muecke WITNESS Aug. 14, 1956 Filed Dec. 8, 1954W/TNESS E. A. MUECKE LOOPERS AND LOOPER THROW-OUTS FOR CHAIN-STITCHSEWING MACHINES 3 Sheets-Sheet 2 Fig.2.

INVENTOR.

- Edward A.Muecke ATTORNEY Aug. 14, 1956 E. A. MUECKE 2 7 LOOPERS ANDLOOPER THROW-OUTS FOR CHAIN-STITCH SEWING MACHINES Filed Dec. 8, 1954 3Sheets-Sheet 3 mmnnnnn IN VEN TOR.

Edward A. Muecke W/TNESS BY ATTORNEY United States Patent LOOPERS ANDLOOPER THROW-OUTS FOR CHAIN-STITCH SEWING MACHINES Edward A. Muecke,Linden, N. 1., assignor to The Singer Manufacturing Company, Elizabeth,N. J., a corporation of New Jersey This invention relates to sewingmachines and more particularly to chain-stitch sewing machines having aplurality of synchronously driven loopers that can easily be positionedto facilitate threading, and one of the principal objects of the presentinvention is the provision of an improved looper mechanism as well as animproved looper throw-out mechanism.

A further object'of the invention is the provision of an improvedmechanism for synchronously driving a pair of loopers and at the sametime providing an improved means whereby the operator can selectivelymove the loopers from a normally inaccessible operating position to aposition easily accessible for threading.

Another object of the invention is the provision of an improved meansfor lubricating a looper mechanism.

A still further object of the invention is the provision of animprovedlooper mechanism arranged sothat the position of the loopers caneasily be adjusted to' correspond with changes in the gauge or spacingof the needles.

With these and other objects in view, as willhereinafter appear, theinvention consists-of the devices, combinations and arrangements ofparts described in connection with the accompanying drawings, whichillustrate a preferred embodiment of the invention and in which:

Fig. 1 is a fragmentary, Vertical, longitudinal sectional view of aportion :of a chain-stitch sewingmachine' embodying the looper throw-outmechanism of this invention;

Fig. 2 is a bottom plan view, with a portion insection, of the sewingmachine shown in Fig. 1;

Fig. 3 is a fragmentary elevational view taken on the line 3-3 of Fig.1, the dash-dash lines showing parts of the looper throw-out moved tothe threading position;

Fig. 4 is a sectional plan view taken along the line 4-4 of Fig. 1;

Fig. 5 is an elevational sectional view taken substantially along theline 5-5 of Fig. 1'; and

Fig. 6 is an exploded perspective view of portions of the looperthrow-out mechanism.

Referring. now in detail to the drawings, the illustrated embodiment ofthe invention is shown asapplied to'a sewing machine which in somerespects is similar to'the one shown in the United States Patent No.2,441,931, issued May 18, 1948, assigned to- The Singer ManufacturingCompany.

The sewing machine, which incorporates the improved looper andthe-improved looper throw-out mechanism of the present invention,comprises a' bed-plate provided with an access opening closed by aremovable cover 16, an" overhanging bracket-arm-head" 17 that supports apresser-bar 18 which in turn supports a presser-foot. 19, andaneedle-bar 20 which in' turn supports a plurality of needles 21-21.Below the bed-plate 15' are supported portions of the sewing machinecomprising a rotary drive shaft 22-having a crank 23 and an eccentric(not shown, but which is illustrated in United States Patent No.2,441,931 supra) by which, respectively, the required endwisereciprocatory or loop-seizing andloopshedding'movements, as well as thevibratory or so-called needle avoiding movements are imparted to a pairof loopers 24 and 24. Each looper is mounted on its own iooper-carrier26 or 26, and each looper-carrier comprises a pivotal'sleeve 25 or 25and a looper-carrier-arm 30 or 3%). Each looper-carrier 26 or 26' is, bymeans of the sleeves 25 or 25', pivotally supported on its ownlcoper-carrier-support, these being designated generafly by the numerals27' and 27'.

The endwise reciprocatory movement of the loopers 24-24 is controlled bythe crank 23 through the medium of a pitman' 28, rock-arms 29 and 29journaled on a stud 3'1, and through a link 32 connecting the rockerarm29, with the looper-carrier 26. The second loopercarrier 26 is connectedto the first looper-carrier 26 by means of a link 33 (Fig. 1) therebycausing the two looper-carriers 26 and 26 to rock in. unison and theirloopers 24-24 to reciprocate in synchronism.

Lateral or sidewise vibrating movements of the loopers are effectedthrough the medium of an eccentric actuating fork 34 (Fig. 2) and atubular or hollow rock-shaft 36 having a bore 35, the shaft 36 extendinglongitudinally of the bedplate 15 and said shaft being journaled inbushings 37 and 38 fitted Within a bearing support 39. Thesupport39'forms a part of a bracket 41 depending from theunderside ofthe bedplate 15 and thus the support 3% carries the rock-shaft 36, oneportion of which supports a looper throw-out device designated by thenumeral 42.

The looper throw-out device 42 (Figs. 3, 4 and 6) includesasubstantially cylindrical plate or collar 43 positioned at a locationapproximately three-fifths of the distance from one end 44 of therock-shaft 36 to the other end 46 thereof. This plate 43 is providedwith an axially extending'latch-notch 47 and a flat 48 adjacent to i oneside of the notch 47. The hollow shorter end 46 of the rock-shaft 36turnably supports a hollow looper-support sleeve 49 (Fig. 4), which mayselectively be connected toor disconnected from the rockshaft36. Forthis purpose the sleeve 49' (Fig. 6) carries a plate 51 at the endrofthe sleeve 49 which is adjacent to the plate 43. Fromone face 52 of thisplate 51 protrudes a block 53 and at one end of the block 53 therefurther protrudes a visor-like member 54, the outer surface of thevisor-like member 54' being provided with a spring-receiving recess 56(Fig. 4). A yoke 57, which has two legs straddling the aforesaid block53 and a convex end 58 connected thereto by screws 59-59, is slidablycarried on the block 53, and positioned between the plates 43 and 51.The convex end 58 of the yoke 57 is biased away from the previouslymentioned visor-like member 54 by means of a helical compression spring61. One end ofv the spring 61 enters the recess 56 in the visor-likemember 54 andthe other end of the spring 61 enters a recess 62 formed inthe convex end 58. The end of the yoke 57 remote from the convex end 58carries a protruding latch-lug 63, which is of such size as to enter theaxially extending latch-notch 47 formed in the plate 43. When the yoke57 is moved in a direction to compress the spring. 61, the latch-lug 63moves out of the latch-notch 47 to' such an extent that, by turning theplate 51, the blocki53 and the yoke- 57 as a unit, the latch-lug 63 maybepositioned to overlie the flat 48 thereby holding the spring 61compressed.

The looper-support-sleeve 49 (Fig. 4) carries the previously mentionedlooper-carrier-supports 27 and 2'7 and each looper-carrier-supportcomprises looper-carrier support bracket 64 or 64 and aloopercarrier-support rock-pin 67 or 67 having bores 65 or 65'. Eachlooper-carrier-support bracket 64-64 is held to the sleeve 49 by a splitmember formed integral with each bracket and forced closed by screws66-66. The rockpins 67-67 pivotally' mount the looper-carriers 26-26Patented Aug. 14, 1956 respectively a which, as previously stated,support the conventional loopers 24-24. The looper-carriers 26-26 arecaused to pivot in unison about the rock-pins 67-67 by means of theconnecting link 33, opposite ends of which are pivotally connected tothe looper-carriers 26and 26' by means of screws 63 and 68. Thelooper-carrier 26 is connected, by means of a ball and socket joint 69and longitudinally adjustable connection 71 to one end of the previouslymentioned link 32.

In order that the loopers 24 and 24 may be adjusted to correspond withchanges in the gauge or spacing between the needles 21-21, thelooper-carrier-support brackets 64 and 64 are spaced (Figs. 1 and 2)from one another by means of a cylindrical spacing sleeve 72. Thelooper-carrier-support bracket 64 is spaced from plate 51 by means of acylindrical spacing sleeve 73, and the loopencarrier-support bracket 64'is spaced from the terminal of the rock-shaft 36 by means of acylindrical sleeve 74. The distance between and the location of thelooper-carrier-support brackets 64-64 and the spacing between and thelocation of the loopers 24-24 can be adjusted and varied by removing thesleeves 72, 73 and 74 and substituting sleeves having diflerent axiallengths. It will be noted that for the purpose of illustration thesleeves 72A, 73A and 74A are shown in Fig. 4 as having different axiallengths than the corresponding sleeve '72, 73 and 74 shown in Figs. 1and 2. The sleeves 72, 73 and 74 or the sleeves 72A, 73A and 74A as wellas the looper-carrier-support brackets 64 and 64 are properly positionedand held on the looper-support sleeve 49 by means of a terminal screw 76which is threaded into the end of the rock-shaft 36. It will beunderstood that the link 33, which is shown in Figs. 1 and 2, will notbe long enough when the sleeves 72A, 73A and 74A shown in Fig. 4 areused. A lengthened link is shown in Fig. 4 as 33A.

The looper throw-out device 42 includes a manually operable unlatchinglever 77 which, by means of a screw 73, is pivotally mounted on the freeend of a bar 79 carried on the bearing support 39 by means of a splitring 81 that is held closed by a clamping screw 82. The lever 77 isbiased to a predetermined position by means of a leaf spring 83 (Figs. 2and 6), one end of which is held to the support bar 79 by means of ascrew 84. The other end of the leaf spring 83 is L-shaped and engages aflattened end 86 of the lever 77. When the lever 77 is moved from thenormal position in which it is held by the spring 83, the spring 83 isflexed sufiiciently so that when the lever 77 is released the spring 83returns the lever 77 to its normal position. The lever 77, at a locationbetween its two ends, carries a screw 87 which rotatably supports aroller 88. When the lever 77 is manipulated, the roller 88 engages theexternal surface of the convex end 58, thereby moving the yoke 57against the action of the compression spring 61. This moves thelatch-lug 63 out of the latch-notch 47 and makes it possible to turn thelooper-support-sleeve 49 and the yoke 57 from the solid line positionshown in Fig. 3 to the position shown in dash-dash lines. This moves theloopers 24 and 24 from an inaccessible operating position to anaccessible threading position, thereby making it possible to thread theloopers with ease. In this connection it will be noted that turning thelooper-support-sleeve 49 and the yoke 57 positions the latch-lug 63above the fiat 48 and holds the yoke 57 in the extended position and thehelical spring 61 compressed. When the loopers 24 and 24- are moved fromthe accessible threading position to the operative position, thelatch-lug 63 snaps back into the latch-notch 47 and assures that theloopers 24-24 will be properly positioned with respect to the needles21-21.

Lubrication In order that the loopers may be actuated at high speeds andfor long periods of time, various parts of the looper 4 mechanism arelubricated by oil under pressure. This oil is supplied from a pump (notshown) to an oil pipe 91 (Fig. 2) which by means of a fitting 92 isconnected to an L-shaped oil duct 93 drilled in a member depending fromthe lower surface of the bed-plate 15. The delivery end (Pig. 1) of theoil duct 93 connects with a bearing groove 94 which in turn communicatesthrough a port 96 and a duct 97 leading to a port 98 formed in thepreviously described bearing bushing 37. The port 93 is connected bymeans of a bearing channel 99 with a cavity formed between the twobearing bushings 37 and 38. From the cavity 101 the oil is forcedthrough a pair of radially disposed ports 162-162 formed in the hollowrock-shaft 36 and thence into the longitudinally extending bore 35. Thebore at the end 44 of the rock-shaft 36 is closed by an aperturedoverflow plug 103, the aperture of which permits excess oil to escapeand flow back to an oil pan (not shown) located below the bed 15. Theoil which does not escape through the apertured plug 103 flows (Fig. 4)toward the other end 46 of the rock-shaft 36. Some of this oil passesthrough radial ports 104-404 formed in the wall of the rockshaft 36thereby lubricating the rock-shaft 36 as it rotates in the bearingbushing 38. Another portion of the oil passes through radial ports106-196 formed in the rocl-:- shaft 36 and thereby enters a cavity 107formed by two circumferential grooves, one groove being formed in theinner surface of the looper-support sleeve 49 and the other groove beingformed in the outer surface of the rock-shaft 36. From the cavity 107the oil passes through ports 108-108 to an axially extending groove 109formed in the external surface of the looper-support sleeve 49. From thegroove 1439 oil passes into the ends of the bores 65 and 65' of therock-pins 67 and 67 and thence through ports 111-111 and 111-111 intocylindrical channels 112 and 112' formed in the inner surfaces of thepivotal sleeves 25-25. The cylindrical channels 112 and 112' (one beingshown in Fig. 5) respectively connect with axially extending grooves113-113 likewise formed in the inner surfaces of the pivotal sleeves 25and 25. Opposite ends of the grooves 113 and 113' are radially extendedas indicated at 114-114 and 114'-114'. This assures that the innercylindrical bore and the two end faces of the pivotal sleeves 25-25 willbe properly lubricated. Oil also passes from the grooves 113 and 113through bores 117-117 (one being shown in Fig. 5) extendinglongitudinally through the looper-carrier-arms 30-30. Oil passes fromthe bores 117-117 to bores 113-118 and thence through ports 119-119 and119-119 formed in the journals which journal the opposed hubs of thepreviously mentioned connecting link 33, it being noted that the ports119-119 and 119-119' discharge into grooves 121-121 formed in the saidhubs of the link 33. Oil also passes from the bore 117 to a bore 122 andthence through a bore 123 thereby lubricating the engaging surfaces ofthe ball and socket joints 69 which connects the link 32 with thelooper-carrier-arm 30. From this it can readily be seen that all movingparts of the looper mechanism are force lubricated and can thus beoperated at high speeds for long periods of time.

Operation The operation of the above described device is apparent fromthe foregoing, however, the operation will be briefly outlined asfollows. The first thing that an operator will do who wishes to threadthe loopers will be to remove the cover 16. Then pressing the upper endof the unlatching lever 77 causes the lever to move against the actionof the leaf-spring 83 and to carry the roller 88 (which as seen in Fig.2 is normally out of contact with the convex end 58) into contact Withthe convex end 58. This moves convex end 58 and the yoke 57 against theaction of the helical spring 61 and frees the latch-lug 63 from thelatch notch 47. Then the operator moves (Fig, 3) the loopers 24-24 froman inaccessible position to an accessible threading position, and alsomoves the latch lug 63 above the flat 48. When the lever 77 is released,the lug 63 rests on the flat 48 and the loopers 24-24 remain inthreading position. After the loopers 24-24 are threaded, the operatormoves the loopers back to the operative position and the latch lug 63automatically snaps into the latch notch 47.

If the operator wishes to change the gauge between the needles 21 and21, the position of the loopers 24-24 are changed correspondingly. Thisis accomplished by removing the terminal screw 76, and loosening thescrews 66-66. Then the sleeve 74, the looper-carrier-support 27', sleeve'72, the looper-carrier-support 27 and the sleeve 73 are removed fromthe looper-support sleeve 49. Thereafter, the looper-carrier-supports 27and 27 are spaced by difierent sized sleeves, for example, sleeves 72A,73A and 74A (Fig. 4) being substituted for the sleeves 72, 73 and 74shown in Figs. 1 and 2. It will,

of course, be understood that sleeves of many different sizes may beused and thus any gauge between the needles 21-21 may be matched byvariations in the spacing between the loopers 24 and 24. The length ofthe link 32 can, of course, be adjusted by varying the adjustableconnection 71. It will also be understood that the link 33 may bereplaced by the link 33A of dilferent length or the length of the link33 may, if desired, be made adjustable in the same manner in which thelink 32 is adjustable.

Lubrication of the looper mechanism which is accomplished by oil flowingthrough the hollow bore 35 of the shaft 36 is automatic in itsoperation. An excess of oil is introduced through the oil pipe 91.Excess oil is discharged through the overflow plug 103 and the rest ofthe oil lubricates all moving parts of the looper mechanism.

Having thus described the nature of the invention, what I claim hereinis:

1. In a looper mechanism for a chain-stitch sewing machine, a bed-platefor said machine, a rock-shaft supported below said bed-plate, a firstplate carried on said rock-shaft, said first plate carrying alatch-member, a looper-support-sleeve journaled on one end of saidrockshaft, a second plate carried on said looper-supportsleeve, saidsecond plate carrying a latch-member, means for moving one of saidlatch-members relative to the plate it is carried by and a manuallyactuated unlatching lever carried by said bed-plate for moving one ofsaid latch members out of engagement with the other latchmember.

2. In a looper mechanism for a chain-stitch sewing machine, a bed-platefor said machine, a rock-shaft supported below said bed-plate, a firstplate carried on said rock-shaft, said first plate being provided with alatchnotch, a looper-support-sleeve journaled on one end of 'saidrock-shaft, a second plate carried on said loopersupport-sleeve, a yokeslidable on said second plate, said yoke being provided with a latch-lugadapted to enter said latch-notch in said first plate, and a manuallyactuated unlatching lever carried by said bed-plate for engaging andmoving said yoke and thereby moving said latch-lug out of saidlatch-notch.

3. In a looper mechanism for a chain-stitch sewing machine, a bed-platefor said machine, a hollow rock shaft supported below said bed-plate, afirst plate carried on said rock-shaft and located between opposite endsthereof, said first plate being provided with a latch-notch and a flat,a looper-support-sleeve journaled on one end of said rock-shaft, asecond plate carried on the end of said looper-support-sleeve which isadjacent to said first piate, said second plate being provided with ablock and a visor-like member, a yoke positioned between said two platesand slidable on said block, said yoke being provided with a latch-lugadapted to enter said latch-notch in said first plate, a helicalcompression spring positioned between said visor-like member and saidyoke and biasing said latch-lug into said latch-notch, and a manuallyactuated unlatching lever carried by said bed-plate for engaging andmoving said yoke against the compression of said spring and therebymoving said latch-lug out of said latch-notch.

4. In a looper mechanism for a chain-stitch sewing machine, a bed-platefor said machine, a hollow rockshaft supported below said bed-plate, alooper-supportsleeve journaled on said rock-shaft, latch means forselectively connecting and disconnecting said looper-supportsleeve andsaid rock-shaft, a plurality of looper-supportbrackets mounted on saidlooper-support-sleeve, means for selectively securing saidlooper-support-brackets to various locations on saidlooper-support-sleeve, a loopercarrier pivotally mounted on each of saidlooper-supportbrackets, a looper carried on each looper-carrier, andmeans for lubricating the moving parts associated with saidlooper-support-sleeve, said looper-support-bracket and saidlooper-carrier. a 5. In a looper mechanism for a chain-stitch sewingmachine, a bed-plate for said machine, a hollow rockshaft supportedbelow said bed-plate, a first plate carried on said rock-shaft andlocated between opposite ends thereof, said plate being provided with alatch-notch and a flat, a looper-support-sleeve journaled on one end ofsaid rock-shaft, a second plate carried on the end of saidlooper-support-sleeve which is adjacent to said first plate, said secondplate being provided with a block and a visor-like member, a yokepositioned between said two plates and slidable on said block, said yokebeing provided with a latch-lug adapted to enter said latch-notch insaid first plate, a helical compression spring positioned between saidvisor-like member and said yoke and biasing said latch-lug into saidlatch-notch, a manual unlatching lever carried by said bed-plate forengaging and moving said yoke against the compression of said spring andthereby moving said latch-lug out of said latch-notch, a plurality oflooper-support-brackets mounted on said looper-support-sleeve, arock-pin carried by each of said looper-support-brackets, alooper-carrier-sleeve pivotally mounted on each of said rock-pins, alooper-carrier-arm secured to each of said looper-carrier-sleeves, alooper carried on each looper-carrier-arm, means for pivotally movingsaid looper-carrier-sleeves and loop-carrier-arms on said rock-pins, andmeans for lubricating all moving parts of said looper mechanism.

References Cited in the file of this patent UNITED STATES PATENTS1,915,923 Clayton June 27, 1933 2,397,336 Clayton Mar. 26, 19462,441,931 Clayton May 18, 1948 2,630,088 Muecke Mar. 3, 1953

